If you are getting below issue :
After creating linked server and when you try to run the query using ssms
select * from OpenQuery(ORACLE_LINK, 'select * from xxx_table_history')
you get encounter below issue.
Cannot create an instance of OLE DB db provider "oraOLEDB.Oracle" for linked server "ORACLE_LINK"
Execute permission was denied on the object 'xp_prop_oledb_provider', database 'mssqlsystemresource', schema 'sys' (Microsoft SQL Server, Error 229)
Login to the server where you are getting this error go to
Server Objects --> Linked servers --> Providers --> right click on [OraOLEDB.Oracle] and select properties
In properties window click on ALLOW INPROCESS